document.write( "Question 1148882: The denominator of a fraction is five more than twice the numerator. If both numerator and denominator are decreased by seven, the simplified result is 1/6.
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document.write( ". Find the original fraction. (Do NOT simplify.) \n" );
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Algebra.Com's Answer #770204 by jim_thompson5910(35256)![]() ![]() ![]() You can put this solution on YOUR website! \n" ); document.write( "Answer: 10/25 \n" ); document.write( "=============================================== \n" ); document.write( "Work Shown:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Let \n" ); document.write( "n = original numerator \n" ); document.write( "d = original denominator\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "We know that d = 2n+5 since \"The denominator of a fraction is five more than twice the numerator\"\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "\"If both numerator and denominator are decreased by seven, the simplified result is 1/6\" meaning that (n-7)/(d-7) = 1/6\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Let's solve for n after doing a substitution \n" ); document.write( "(n-7)/(d-7) = 1/6 \n" ); document.write( "(n-7)/(2n+5-7) = 1/6 ... replace d with 2n+5 \n" ); document.write( "(n-7)/(2n-2) = 1/6 \n" ); document.write( "6(n-7) = 1(2n-2) .... cross multiply \n" ); document.write( "6n-42 = 2n-2 \n" ); document.write( "6n-42-2n = 2n-2-2n ... subtract 2n from both sides \n" ); document.write( "4n-42 = -2 \n" ); document.write( "4n-42+42 = -2+42 ... add 42 to both sides \n" ); document.write( "4n = 40 \n" ); document.write( "4n/4 = 40/4 ... divide both sides by 4 \n" ); document.write( "n = 40/4 \n" ); document.write( "n = 10\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "If n = 10, then d is \n" ); document.write( "d = 2n+5 \n" ); document.write( "d = 2*10+5 \n" ); document.write( "d = 20+5 \n" ); document.write( "d = 25\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So n/d = 10/25 is the original fraction (we arent reducing it). After decreasing the numerator and denominator by 7, we end up with 3/18 = 1/6, which confirms our answer. \n" ); document.write( " \n" ); document.write( " |